Keldagrim key mould 6 is an item used during the King of the Dwarves quest. It is made by giving six soft clay to Meike, who will give back the moulds after the player has distracted the librarian. If used on a furnace with a mithril bar in inventory, the bar will become a Keldagrim key 6. The moulds can be kept after the quest, but they have no use.